Mehmet Orgun
Macquarie University, Computing, Faculty Member
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Research in event detection from the Twitter streaming data has been gaining momentum in the last couple of years. Although such data is noisy and often contains misleading information, Twitter can be a rich source of information if... more
Research in event detection from the Twitter streaming data has been gaining momentum in the last couple of years. Although such data is noisy and often contains misleading information, Twitter can be a rich source of information if harnessed properly. In this paper, we propose a scalable event detection system, TwitterNews, to detect and track newsworthy events in real time from Twitter. TwitterNews provides a novel approach, by combining random indexing based term vector model with locality sensitive hashing, that aids in performing incremental clustering of tweets related to various events within a fixed time. TwitterNews also incorporates an effective strategy to deal with the cluster fragmentation issue prevalent in incremental clustering. The set of candidate events generated by TwitterNews are then filtered, to report the newsworthy events along with an automatically selected representative tweet from each event cluster. Finally, we evaluate the effectiveness of TwitterNews, ...
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Social media has enabled information-sharing across massively large networks of people without spending much financial resources and time that are otherwise required in the print and electronic media. Mobile-based social media... more
Social media has enabled information-sharing across massively large networks of people without spending much financial resources and time that are otherwise required in the print and electronic media. Mobile-based social media applications have overwhelmingly changed the information-sharing perspective. However, with the advent of such applications at an unprecedented scale, the privacy of the information is compromised to a larger extent if breach mitigation is not adequate. Since healthcare applications are also being developed for mobile devices so that they also benefit from the power of social media, cybersecurity privacy concerns for such sensitive applications have become critical. This article discusses the architecture of a typical mobile healthcare application, in which customized privacy levels are defined for the individuals participating in the system. It then elaborates on how the communication across a social network in a multi-cloud environment can be made more secur...
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Quantum cryptography is commonly used to generate fresh secure keys with quantum signal transmission for instant use between two parties. However, research shows that the relatively low key generation rate hinders its practical use where... more
Quantum cryptography is commonly used to generate fresh secure keys with quantum signal transmission for instant use between two parties. However, research shows that the relatively low key generation rate hinders its practical use where a symmetric cryptography component consumes the shared key. That is, the security of the symmetric cryptography demands frequent rate of key updates, which leads to a higher consumption of the internal one-time-pad communication bandwidth, since it requires the length of the key to be as long as that of the secret. In order to alleviate these issues, we develop a matrix algorithm for fast and simple high-capacity quantum cryptography. Our scheme can achieve secure private communication with fresh keys generated from Fibonacci- and Lucas- valued orbital angular momentum (OAM) states for the seed to construct recursive Fibonacci and Lucas matrices. Moreover, the proposed matrix algorithm for quantum cryptography can ultimately be simplified to matrix ...
E-Healthcare is an emerging field that provides mobility to its users. The protected health information of the users are stored at a remote server (Telecare Medical Information System) and can be accessed by the users at anytime. Many... more
E-Healthcare is an emerging field that provides mobility to its users. The protected health information of the users are stored at a remote server (Telecare Medical Information System) and can be accessed by the users at anytime. Many authentication protocols have been proposed to ensure the secure authenticated access to the Telecare Medical Information System. These protocols are designed to provide certain properties such as: anonymity, untraceability, unlinkability, privacy, confidentiality, availability and integrity. They also aim to build a key exchange mechanism, which provides security against some attacks such as: identity theft, password guessing, denial of service, impersonation and insider attacks. This paper reviews these proposed authentication protocols and discusses their strengths and weaknesses in terms of ensured security and privacy properties, and computation cost. The schemes are divided in three broad categories of one-factor, two-factor and three-factor authentication schemes. Inter-category and intra-category comparison has been performed for these schemes and based on the derived results we propose future directions and recommendations that can be very helpful to the researchers who work on the design and implementation of authentication protocols.
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With prevalent attacks in communication, sharing a secret between communicating parties is an ongoing challenge. Moreover, it is important to integrate quantum solutions with classical secret sharing schemes with low computational cost... more
With prevalent attacks in communication, sharing a secret between communicating parties is an ongoing challenge. Moreover, it is important to integrate quantum solutions with classical secret sharing schemes with low computational cost for the real world use. This paper proposes a novel hybrid threshold adaptable quantum secret sharing scheme, using an m-bonacci orbital angular momentum (OAM) pump, Lagrange interpolation polynomials, and reverse Huffman-Fibonacci-tree coding. To be exact, we employ entangled states prepared by m-bonacci sequences to detect eavesdropping. Meanwhile, we encode m-bonacci sequences in Lagrange interpolation polynomials to generate the shares of a secret with reverse Huffman-Fibonacci-tree coding. The advantages of the proposed scheme is that it can detect eavesdropping without joint quantum operations, and permits secret sharing for an arbitrary but no less than threshold-value number of classical participants with much lower bandwidth. Also, in compari...
... living cells. However, the most important application of such discovery is in drug design, as pathological effects of a drug can only be addressed with precise knowledge of what functions and dysfunctions really are. Living cells ...
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Abstract. Data mining, often called knowledge discovery in databases (KDD), aims at semiautomatic tools for the analysis of large data sets. This report is first intended to serve as a timely overview of a rapidly emerging area of... more
Abstract. Data mining, often called knowledge discovery in databases (KDD), aims at semiautomatic tools for the analysis of large data sets. This report is first intended to serve as a timely overview of a rapidly emerging area of research, called temporal data mining (that is, data mining ...
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This paper aims to study the concept of a distributed World Wide Web archive that complements the existing WWW and "lives" across a vast Peer-to-Peer network of broadband-connected user nodes. It proposes the sharing of... more
This paper aims to study the concept of a distributed World Wide Web archive that complements the existing WWW and "lives" across a vast Peer-to-Peer network of broadband-connected user nodes. It proposes the sharing of a web browser's cached data with other peers in an effort to provide an alternative resource to "discontinued" web documents with [normally] short life spans such as video and audio content as well as frequently restructured text pages. We have based this study on the success of existing file-sharing Peer-to-Peer networks and aim to extend their use further to facilitate content-oriented usage more appropriately while at the same time, addressing some of the major problems that arise from this.
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... Yan Wang Department of Computing Macquarie University Sydney, NSW 2109, Australia yanwang@science.mq.edu.au Mehmet Orgun Department of Computing Macquarie University Sydney, NSW 2109, Australia mehmet@science.mq.edu.au Abstract ...
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Finding a global optimum of an unknown system has attracted a great deal of interest in many engineering problems. In this settings, meta-heuristics are very common as efficient approaches for solving complex real-world problems in global... more
Finding a global optimum of an unknown system has attracted a great deal of interest in many engineering problems. In this settings, meta-heuristics are very common as efficient approaches for solving complex real-world problems in global continuous optimization problems (GCOPs) as they can approximate solutions without considering mathematical constraints such as differentiability. In this study, we propose a method based
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There are multi-versioning schemes that can preserve individual users’ concurrent conflicting intentions in a consistent way. However, they are proposed for intention preservation in collaborative editing environments, where a document... more
There are multi-versioning schemes that can preserve individual users’ concurrent conflicting intentions in a consistent way. However, they are proposed for intention preservation in collaborative editing environments, where a document consists of a set of independent objects with independent attributes. In order to support unconstrained collaborative editing on text objects, this paper proposes an integrated operational transformation and multi-versioning scheme
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Page 1. A Temporal Paraconsistent Relational Algebra for Incomplete and Inconsistent Information Rajiv Bagai Department of Computer Science Wichita State University Wichita, KS 67260-0083, USA bagai@cs.twsu.edu Mehmet ...
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AbstractSecurity and trust are fundamental challenges when it comes to the deployment of large wireless sensor networks. In this paper, we propose a novel hierarchical trust management scheme that minimizes communication and storage... more
AbstractSecurity and trust are fundamental challenges when it comes to the deployment of large wireless sensor networks. In this paper, we propose a novel hierarchical trust management scheme that minimizes communication and storage overheads. Our scheme takes into ...
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The deployment of intelligent remote surveillance systems depends on wireless sensor networks (WSNs) composed of various miniature resource-constrained wireless sensor nodes. The development of routing protocols for WSNs is a major... more
The deployment of intelligent remote surveillance systems depends on wireless sensor networks (WSNs) composed of various miniature resource-constrained wireless sensor nodes. The development of routing protocols for WSNs is a major challenge because of their severe resource constraints, ad hoc topology and dynamic nature. Among those proposed routing protocols, the biology-inspired self-organized secure autonomous routing protocol (BIOSARP) involves an artificial immune system (AIS) that requires a certain amount of time to build up knowledge of neighboring nodes. The AIS algorithm uses this knowledge to distinguish between self and non-self neighboring nodes. The knowledge-building phase is a critical period in the WSN lifespan and requires active security measures. This paper proposes an enhanced BIOSARP (E-BIOSARP) that incorporates a random key encryption mechanism in a cost-effective manner to provide active security measures in WSNs. A detailed description of E-BIOSARP is pres...
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Page 1. Using Dynamic Bayesian Networks to Infer Gene Regulatory Networks from Expression Profiles Akther Shermin Macquarie University Department of Computing NSW 2109, Australia ashermin@ics.mq.edu.au Mehmet ...
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Chronolog(Z) is a logic programming language based on a linear-time temporal logic withunbounded past and future. By adding "choice predicates" to Chronolog(Z), it is possibleto obtain exactly one answer... more
Chronolog(Z) is a logic programming language based on a linear-time temporal logic withunbounded past and future. By adding "choice predicates" to Chronolog(Z), it is possibleto obtain exactly one answer to a given goal when we want to model dataflow style ofstream-oriented computations. This paper, based on the framework we propose for exploitingparallelism in Chronolog, discusses and enhances the parallel execution
As defined by IEEE 802.15.6 standard, channel sharing is a potential method to coordinate inter-network interference among Medical Body Area Networks (MBANs) that are close to one another. However, channel sharing opens up new... more
As defined by IEEE 802.15.6 standard, channel sharing is a potential method to coordinate inter-network interference among Medical Body Area Networks (MBANs) that are close to one another. However, channel sharing opens up new vulnerabilities as selfish MBANs may manipulate their online channel requests to gain unfair advantage over others. In this paper, we address this issue by proposing a truthful online channel sharing algorithm and a companion protocol that allocates channel efficiently and truthfully by punishing MBANs for misreporting their channel request parameters such as time, duration and bid for the channel. We first present an online channel sharing scheme for unit-length channel requests and prove that it is truthful. We then generalize our model to settings with variable-length channel requests, where we propose a critical value based channel pricing and preemption scheme. A bid adjustment procedure prevents unbeneficial preemption by artificially raising the ongoing...
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... Ali Orhan Aydin Mehmet Ali Orgun Department of Computing, Macquarie University NSW 2109, Sydney, Australia +90-555-679-8073, +61-2-9850-9570 ali.aydin@mq.edu.au, mehmet.orgun@ mq.edu.au Keywords: Models of Decision Making,... more
... Ali Orhan Aydin Mehmet Ali Orgun Department of Computing, Macquarie University NSW 2109, Sydney, Australia +90-555-679-8073, +61-2-9850-9570 ali.aydin@mq.edu.au, mehmet.orgun@ mq.edu.au Keywords: Models of Decision Making, Reactive-Causal Architecture ...
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